// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_GL_GL_GL_API_IMPLEMENTATION_H_
#define UI_GL_GL_GL_API_IMPLEMENTATION_H_

#include <vector>

#include "base/compiler_specific.h"
#include "ui/gl/gl_bindings.h"
#include "ui/gl/gl_export.h"

namespace base {
class CommandLine;
}
namespace gpu {
namespace gles2 {
    class GLES2Decoder;
}
}
namespace gfx {

class GLContext;
class GLSurface;
struct GLVersionInfo;

void InitializeStaticGLBindingsGL();
void InitializeDynamicGLBindingsGL(GLContext* context);
void InitializeDebugGLBindingsGL();
void InitializeNullDrawGLBindingsGL();
// TODO(danakj): Remove this when all test suites are using null-draw.
bool HasInitializedNullDrawGLBindingsGL();
bool SetNullDrawGLBindingsEnabledGL(bool enabled);
void ClearGLBindingsGL();
void SetGLToRealGLApi();
void SetGLApi(GLApi* api);
void SetGLApiToNoContext();
GLApi* GetCurrentGLApi();
const GLVersionInfo* GetGLVersionInfo();

class GL_EXPORT GLApiBase : public GLApi {
public:
// Include the auto-generated part of this class. We split this because
// it means we can easily edit the non-auto generated parts right here in
// this file instead of having to edit some template or the code generator.
#include "gl_bindings_api_autogen_gl.h"

protected:
    GLApiBase();
    ~GLApiBase() override;
    void InitializeBase(DriverGL* driver);

    DriverGL* driver_;
};

// Implemenents the GL API by calling directly into the driver.
class GL_EXPORT RealGLApi : public GLApiBase {
public:
    RealGLApi();
    ~RealGLApi() override;
    void Initialize(DriverGL* driver);
    void InitializeWithCommandLine(DriverGL* driver,
        base::CommandLine* command_line);

    void glGetIntegervFn(GLenum pname, GLint* params) override;
    const GLubyte* glGetStringFn(GLenum name) override;
    const GLubyte* glGetStringiFn(GLenum name, GLuint index) override;

    void InitializeFilteredExtensions();

private:
    void glFinishFn() override;
    void glFlushFn() override;

    // Filtered GL_EXTENSIONS we return to glGetString(i) calls.
    std::vector<std::string> disabled_exts_;
    std::vector<std::string> filtered_exts_;
    std::string filtered_exts_str_;

#if DCHECK_IS_ON()
    bool filtered_exts_initialized_;
#endif
};

// Inserts a TRACE for every GL call.
class TraceGLApi : public GLApi {
public:
    TraceGLApi(GLApi* gl_api)
        : gl_api_(gl_api)
    {
    }
    ~TraceGLApi() override;

// Include the auto-generated part of this class. We split this because
// it means we can easily edit the non-auto generated parts right here in
// this file instead of having to edit some template or the code generator.
#include "gl_bindings_api_autogen_gl.h"

private:
    GLApi* gl_api_;
};

// Catches incorrect usage when GL calls are made without a current context.
class NoContextGLApi : public GLApi {
public:
    NoContextGLApi();
    ~NoContextGLApi() override;

// Include the auto-generated part of this class. We split this because
// it means we can easily edit the non-auto generated parts right here in
// this file instead of having to edit some template or the code generator.
#include "gl_bindings_api_autogen_gl.h"
};

// Implementents the GL API using co-operative state restoring.
// Assumes there is only one real GL context and that multiple virtual contexts
// are implemented above it. Restores the needed state from the current context.
class VirtualGLApi : public GLApiBase {
public:
    VirtualGLApi();
    ~VirtualGLApi() override;
    void Initialize(DriverGL* driver, GLContext* real_context);

    // Sets the current virutal context.
    bool MakeCurrent(GLContext* virtual_context, GLSurface* surface);

    void OnReleaseVirtuallyCurrent(GLContext* virtual_context);

private:
    // Overridden functions from GLApiBase
    void glGetIntegervFn(GLenum pname, GLint* params) override;
    const GLubyte* glGetStringFn(GLenum name) override;
    const GLubyte* glGetStringiFn(GLenum name, GLuint index) override;
    void glFinishFn() override;
    void glFlushFn() override;

    // The real context we're running on.
    GLContext* real_context_;

    // The current virtual context.
    GLContext* current_context_;

    // The supported extensions being advertised for this virtual context.
    std::string extensions_;
    std::vector<std::string> extensions_vec_;
};

} // namespace gfx

#endif // UI_GL_GL_GL_API_IMPLEMENTATION_H_
